**Preface to "Land Use Conflict Detection and Multi-Objective Optimization Based on the Productivity, Sustainability, and Livability Perspective"**

Land use affects many aspects of regional sustainable development, so insight into its influence is of great importance for the optimization of national space. With the rapid economic growth and the accelerating industrialization, there has been a noticeable increase in the contention and conflict between various land uses. For example, the expansion of urban and industrial land has occupied a large amount of high-quality farmland, leading to serious contradictions between socioeconomic development and the protection of cultivated land resources. Solving these problems has thus become an important scientific proposition for regional sustainable development in the field of human-economic geography. Based on the widely recognized development goals based on productivity, sustainability, and livability perspectives, a scientific classification system, spatial conflict detection, and multi-objective optimization of land use functions (LUFs) have provided an efficient means for land use planning and management, attracting the extensive attention of researchers and policymakers. For example, production–living–ecological space (PLE), the shortened form for productive space (PS), living space (LS), and ecological space (ES), is reclassified considering both land use functions and utilization types based on productivity, sustainability, and livability perspectives. First proposed by the Chinese Government Report in 2012, it has made prominent contributions to improving the protection system of spatial development while implementing major function-oriented zoning at all scales. Successful implementation in China proves that PLE holds promotional value to provide support for space use allocation, land use conflict management, and sustainable development. However, compared to the literature available on functional classification and identification based on productivity, sustainability, and livability perspectives, it is surprising that very few among the increasing number of papers dealing with LUFs are devoted to its conflict detection and multi-objective optimization with land use planning, which has left many significant questions unanswered. There are few reports on integrated research, and international practical application is especially lacking. Thus, the theoretical research and practical applications of the multi-functional complexity of land use still need to be further refined.

This Special Issue entitled "Land Use Conflict Detection and Multi-Objective Optimization Based on Productivity, Sustainability, and Livability Perspectives" mainly focuses on functional classification, spatial conflict detection, and spatial development pattern optimization based on productivity, sustainability, and livability perspectives, presenting a relevant opportunity for all scholars to share their knowledge from the multidisciplinary community across the world that includes landscape ecologists, social scientists, and geographers. Further progress in theoretical research and practical applications on the scientific classification system toward productivity, sustainability, and livability, such as PLE classification of China, is covered. Integrative studies regarding suitability evaluation and optimized modes of e multi-functional land use systems to meet the target of geographical space optimization and regional sustainable development are also presented.

> **Dong Jiang , Jinwei Dong, and Gang Lin** *Editors*
